1. Field of the Invention
The invention is directed to a torsional vibration damper.
2. Description of the Prior Art
German reference DE-GM 94 14 314 discloses a torsional vibration damper having a transmission element on the driving side and a planet carrier which is in a working connection with the transmission element. The plant carrier is provided with a plurality of bearings, each of which receives a planet gear. The planet gears engage at one end with a ring gear and at the other end with a sun gear. Depending upon the construction of the torsional vibration damper, a transmission element on the driven side is associated with one of the elements of the planetary gear unit, i.e., the sun gear, ring gear or planet carrier. Either the driven-side transmission element or the driving-side transmission element has controlling means for an elastic arrangement in the form of springs which extend in the circumferential direction and are supported at the other end at one of the elements of the planetary gear unit mentioned above.
In such torsional vibration dampers having a planetary gear unit, it is conventional, when the planet gears are mounted on their respective bearing provided at the planet carriers, to lubricate the contact point between the bearing and the radial inner side of the respective planet gear or to apply lubricant to the bearing itself. During operation of the torsional vibration damper, an ever increasing proportion of this lubricant exits at the bearing or at the contact point between the bearing and planet gear, while the remaining lubricant undergoes an aging process. This causes increased wear at the aforementioned contact point, which in turn leads to disadvantageous behavior in the meshing area of the toothings owing to inexact guidance of the planet gears caused by this wear.